Viral oncogenesis in cancer: from mechanisms to therapeutics

The year 2024 marks the 60th anniversary of the discovery of the Epstein-Barr virus (EBV), the first virus confirmed to cause human cancer. Viral infections significantly contribute to the global cancer burden, with seven known Group 1 oncogenic viruses, including hepatitis B virus (HBV), human papillomavirus (HPV), EBV, Kaposi sarcoma-associated herpesvirus (KSHV), hepatitis C virus (HCV), human T-cell leukemia virus type 1 (HTLV-1), and human immunodeficiency virus (HIV). These oncogenic viruses induce cellular transformation and cancer development by altering various biological processes within host cells, particularly under immunosuppression or co-carcinogenic exposures. These viruses are primarily associated with hepatocellular carcinoma, gastric cancer, cervical cancer, nasopharyngeal carcinoma, Kaposi sarcoma, lymphoma, and adult T-cell leukemia/lymphoma. Understanding the mechanisms of viral oncogenesis is crucial for identifying and characterizing the early biological processes of virus-related cancers, providing new targets and strategies for treatment or prevention. This review first outlines the global epidemiology of virus-related tumors, milestone events in research, and the process by which oncogenic viruses infect target cells. It then focuses on the molecular mechanisms by which these viruses induce tumors directly or indirectly, including the regulation of oncogenes or tumor suppressor genes, induction of genomic instability, disruption of regular life cycle of cells, immune suppression, chronic inflammation, and inducing angiogenesis. Finally, current therapeutic strategies for virus-related tumors and recent advances in preclinical and clinical research are discussed.